1. Field of the Invention
The present invention relates to a parking support unit and a parking support method for assisting a steering operation of a motor vehicle during parallel parking, garaging, etc. of the vehicle.
2. Related Art
A conventional one of such units is disclosed in Japanese Patent Application Laid-open No. 2000-79860. This unit displays a predicted vehicle route determined based on a steering angle during parking on a display screen positioned near a driver""s seat. In connection with the predicted vehicle route, a window for finding white guide lines of a parking bay is prepared on the screen.
The window is moved on the screen for finding positions and orientations of the white lines to determine a geometrical arrangement of the parking bay. The unit provides a phonic advice of vehicle steering for a driver in consideration of the parking operation.
The conventional unit requires a complicated image processing for finding the white lines of the parking bay based on image information obtained by a camera. Thus, the unit needs a CPU having a higher process speed, disadvantageously increasing the cost of the unit.
Furthermore, the unit cannot be useful to guide the vehicle when there are no white lines in a parking bay and in a space between other stopped vehicles on a road, limiting the usage of the unit.
In view of the foregoing disadvantage of the conventional unit, an object of the invention is to provide a parking support unit and a parking support method for assisting a steering operation of a motor vehicle to correctly guide the vehicle into a parking bay. The vehicle can be moved backward according to a predicted vehicle route indicated on a display screen during a parking operation of the vehicle.
A parking support unit according to the present invention, as illustrated in a basic block diagram of FIG. 1, includes:
an image pickup means 101 for picking up an image FI of a rear area behind a motor vehicle, the rear area located at a predetermined position relative to the vehicle,
a display means 102 for displaying the rear area image FI,
a steering angle sensing means 103,
a vehicle position sensing means 104,
an image storing means 105 for storing a vehicle image VI, a predicted vehicle route image TR1, and an actual vehicle route image TR2 of the vehicle, and
an image superposing means 106,
wherein the vehicle image VI is superposed on a desired parking position P of the vehicle in the rear area image FI indicated by the display means 102, and the predicted vehicle route image TR1 is generated within the predetermined area based on a steering angle and an initial position of the vehicle, while the actual vehicle route image TR2 is generated based on actual steering angles and positions of the vehicle, the image superposing means 106 indicating the vehicle image V1, the predicted vehicle route image TR1, and the actual vehicle route image TR2 by the display means 102 to superpose them on the rear area image FI.
Thus, the predicted vehicle route image TR1 showing a predicted vehicle route from the present stopped position to a desired parking position is superposed on the rear area image FI indicated on the screen. Furthermore, the actual vehicle route image TR2 is generated based on actual steering angles and positions of the vehicle while the vehicle moves backward from the present stopped position to the desired parking position, and the actual vehicle route image TR2 is superposed on the predicted vehicle route image TR1. A difference between the predicted vehicle route image TR1 and the actual vehicle route image TR2 is used for an appropriate operation correction of a steering wheel by a driver. Accordingly, the driver can move backward the vehicle even to a parking space having no guide lines for parking the vehicle.
The unit, an illustrated in FIG. 1, further has a computing means 107 for obtaining a difference between the predicted vehicle route image TR1 and the actual vehicle route image TR2 and a message informing means 108 for informing a steering angle correction message based on the difference.
Thus, the driver can advantageously know a deviation of the vehicle from a predicted vehicle route image TR1 at an earlier stage of the parking operation, so that the driver can correct the deviation to park the vehicle with ease.
Preferably, the computing means 107 has a decision device 73 for determining a steering direction and a steering amount based on the difference between the predicted vehicle route image TR1 and the actual vehicle route image TR2 to correct the difference. The decision is noticed by the message informing means 108.
Preferably, the computing means 107 has a decision device 71 for determining whether the vehicle can be moved backward to a desired parking position from the present position of the vehicle within a maximum steering angle of the vehicle. The decision is noticed by a voice of the message informing means 108. This allows the driver not to repeat a parking operation toward a parking bay
Preferably, the computing means 107 has a calculating device 72 for calculating a preliminary forwarding distance which is necessary for the vehicle to be moved to a desired parking position from the present position of the vehicle within a maximum steering angle of the vehicle. The result is noticed by a voice of the message informing means 108. Thus, when it is determined that the vehicle can not be moved backward to a desired parking position, the message informing means 108 gives a preliminary forwarding distance of the vehicle to enable the parking at the desired parking position. Thus, the driver can know a correct start point for moving backward the vehicle with ease, enabling an efficient parking operation of the vehicle.
A parking support method according to the present invention includes the steps of:
picking up an image FI of a rear area behind a motor vehicle, the rear area located at a predetermined position relative to the vehicle,
displaying the rear area image FI,
sensing a steering angle of the vehicle,
sensing a position of the vehicle,
storing a vehicle image V1, a predicted vehicle route image TR1, and an actual vehicle route image TR2 of the vehicle, and indicating the vehicle image V1, the predicted vehicle route image TR1, and the actual vehicle route image TR2,
wherein the vehicle image VI is superposed on a desired parking position P of the vehicle in the rear area image FI, and the predicted vehicle route image TR1 is generated within the predetermined area based on a steering angle and an initial position of the vehicle, while the actual vehicle route image TR2 is generated based on actual steering angles and positions of the vehicle, the indicating step indicating the vehicle image V1, the predicted vehicle route image TR1, and the actual vehicle route image TR2 to superpose them on the rear area image FI.
Thus, the predicted vehicle route image TR1 showing a predicted vehicle route from the present stopped position to a desired parking position is superposed on the rear area image FI indicated on the screen. Furthermore, the actual vehicle route image TR2 is generated based on actual steering angles and positions of the vehicle while the vehicle moves backward from the present stopped position to the desired parking position, and the actual vehicle route image TR2 is superposed on the predicted vehicle route image TR1. A difference between the predicted vehicle route image TR1 and the actual vehicle route image TR2 is used for an appropriate correction of a steering wheel operation by a driver.
The method further has a step for obtaining a difference between the predicted vehicle route image TR1 and the actual vehicle route image TR2 and another step for informing a steering angle correction message based on the difference. Thus, the method can output a steering wheel turning direction based on the deference between the predicted vehicle route image TR1 and the actual vehicle route image TR2.
Preferably, the method further has a step for determining a steering direction and a steering amount based on the difference between the predicted vehicle route image TR1 and the actual vehicle route image TR2 to correct the difference. The decision is noticed by the message informing means 108.
Preferably, the method further has a step for determining whether the vehicle can be moved backward to a desired parking position from the present position of the vehicle within a maximum steering angle of the vehicle. The decision is noticed by the message informing means 108.
Preferably, the method has a step for calculating a preliminary forwarding distance which is necessary for the vehicle to be moved to a desired parking position from the present position of the vehicle within a maximum steering angle of the vehicle. The result is noticed by a voice of the message informing means 108. Thus, when it is determined that the vehicle can not be moved backward to a desired parking position, the message informing means 108 informs the preliminary forwarding distance of the vehicle by a voice to enable the parking at the desired parking position.